The present invention relates to industrial control systems and more particularly to industrial control systems having rail-mounted controller and input/output modules.
Industrial control systems, such as distributed control systems, often include one or more controllers that utilize input signals from field devices, such as flow meters, to provide control output signals to final control elements, such as valves, in order to control a process or one or more sub-processes. Such control systems are typically module-based and include one or more controller modules and one or more input/output (I/O) modules through which the controller module receives and sends input and output signals from and to the field, respectively. The controller module and I/O modules are often mounted to a rail, such as a DIN rail.
Rail-mounted control systems must have a flexible design that permits different types and numbers of I/O modules to be connected together with the controller module. In addition, the design should permit modules to be mounted to and removed from the rail in a relatively simple manner. However, this simplicity must be balanced with the need to keep the modules securely fastened to the rail. This balance is often not achieved with conventional rail-mounted control systems.
The present invention is directed to a rail-mounted control system having improved features, including an improved module mounting feature.